I load bismuth #2 with buffer for both my 10 gauge guns, Mark. One is an 1885 Lefever C, and the other is a 1930s or 40s Darne 10 gauge with steel barrels. No problem at all with the Lefever. My understanding is that bismuth is a lead near equivalent and very, very unlikely to damage damascus barrels. Risk was, rather, that the pellets would shatter on hitting a big bird or in contact with barrels walls; hence the buffer. What I now prefer is NICE shot (google it) that is as close to lead as non-toxics can get.
Regards, Tim
